The present disclosure generally relates to refrigeration valves, and more particularly, to an improved refrigeration valve having a universal main body, preferably formed from investment-cast, stainless-steel or other suitable material, that may be used in connection with any number of adapter plates that have been configured to operate the valve to accomplish any function in a commercial or industrial refrigeration system. The adapter plates are preferably formed from an easily machined and drilled, lightweight material, such as aluminum, and anodized to prevent corrosion, or any other suitable material. The improved valve has an inlet and an outlet, each with a flangeless distal end configured, as cast or formed, with an unmachined, weldable rim for integration into the commercial or industrial refrigeration system without mechanical connections in a leak-free configuration.
Closed cycle refrigeration systems have been in use for approximately at least 100 years. During that time many improvements have been made to the elements of the basic system in order to achieve better efficiencies, controllability, temperature ranges, safety, lower temperatures, greater capacities, reduced weight, compactness, reliability, flexibility, and other refinements.
The simplest refrigeration systems involve a Carnot fluid cycle in a closed circuit. Usually the fluid exists as a liquid for certain temperature and pressure conditions, as a gas for other conditions, and a two-phase liquid and gas for other conditions. In a certain location, commonly referred to as an evaporator, as shown in FIG. 1, the mutually contacting liquid and gas or vapor are becoming lesser in liquid percentage and greater in gas percentage as external heat is put into the evaporator. Contrariwise, in a certain location, commonly referred to as a condenser, as shown in FIG. 1, mutually contacting liquid and vapor are becoming greater in liquid percentage and lesser in vapor percentage as heat is removed from the condenser.
In the fluid circuit or conduit between the evaporator and the condenser a mechanical gas compressor or other suitable mechanism, device or apparatus is employed to move the vapor from the lower temperature and pressure of the evaporator to the higher temperature and pressure of the condenser. To control the fluid flow in this closed circuit, a device, commonly referred to as an expansive valve, is used to expand or feed the liquid from the high pressure and temperature condenser to the low pressure and temperature evaporator. For example, FIG. 1 is a simple diagram that illustrates a basic elementary cycle.
Closed-cycle refrigeration systems for use in commercial and industrial applications are typically much more complex than the basic system shown in FIG. 1, involving multiple evaporators, condensers, compressors, expanders, and subsidiary cycles and circuits for multiple temperature levels, for capacity control, for defrosting, for temporary unusual conditions, or for multiple other purposes. For example, FIG. 2 is a diagram that illustrates a typical commercial or industrial system wherein each solid dot indicates the location for installation of at least one control valve.
It will be recognized by those of skill in the art that the most common industrial refrigeration fluid is ammonia, commonly identified by the chemical compound notation NH3. The pressure temperature saturation curve for ammonia is in a range suitable for industrial refrigeration of foodstuffs, beverages, and other cooling processes, generally in the range of +50° F. to −50° F. or thereabouts. The pressures and densities of the liquid and vapor phases of a refrigeration fluid that are within the above-mentioned operational envelope are reasonably compatible with mechanical pipes, compressors, heat exchangers, valves, and other system elements. However, ammonia (NH3) is corrosive to brass and copper, but less corrosive when dry to ferrous metals and certain other alloys. Moreover, NH3 is not only toxic to humans and other living things but it can be harmful to foods and to many other materials in the living environment. Under certain conditions certain mixtures of NH3 and air and the presence of, a hot spark can cause flaming or even explosion. In addition, the smell of ammonia can cause panic among humans and animals. Consequently, the use of ammonia in a refrigeration cycle system must be tightly and safely contained and sealed at all times during normal operation.
Those of skill in the art will also recognize that other fluids may also be used as refrigerants in similar closed cycles, including carbon dioxide, hydrocarbons, fluorocarbons, and other fluids which can exist in liquid or gaseous phases. Such systems must also be sealed against any possibility of leakage from the system to the atmosphere or from the atmosphere to the system for similar reasons. Leakage in either case could cause the system to become inoperative or even dangerous. Consequently, integrity of the system against leakage is of utmost importance and must exist at all anticipated system pressures, temperatures, vibrations, corrosive attacks, or even user misuse.
To overcome the vast temperature, pressure and corrosion demands, conventional commercial and industrial refrigeration valves have thick, oversized-walls which result in a very heavy weight. Such conventional valves are also specialized in design such that they are often unique as per each installation location in the refrigeration system and as a result usually include specialized connections such as flanges for the installation thereof. Still further, conventional valves, are made of common ferrous materials, such as iron, steel or the like, and must be painted or otherwise coated to prevent rust and other degradation.
Refrigeration systems are uniquely different from all other common industrial closed and open fluid circuits including, without limitation hydraulic systems, steam systems, sanitary sewage systems, potable water systems, and many other simple and complicated fluid systems. For such non-refrigeration systems, components exist which can operate satisfactorily for the particular fluids, pressures, temperatures, flow rates, and other unique characteristics. In rare circumstances, certain standardized components might be used in some locations of certain refrigeration systems. Generally, those of skill in the art will acknowledge that those rare circumstances are quite exceptional and that one of skill in the art would recognize that such standardized components are not satisfactory in refrigeration systems due to unsuitable materials, pressure or temperature capability, slight leakage, or other deficiencies.
Specifically, for the valve installation locations shown in the typical commercial or industrial refrigeration piping system shown in FIG. 2, some of the deficiencies would include, without limitation, the following: improper mating connections to system piping, inadequate corrosion resistance, excessive valve weight requiring additional support for the valve and is connecting piping, improper seals to connect the valve parts together, wrong clearances for sliding parts, improper seal designs, excessively high or low working pressure capability, incorrect function of the valve in a refrigeration system, and other characteristics making such standardized components (i.e., special purpose valves or general purpose valves) unsuitable for refrigeration systems. For the above reasons, an entirely unique population of valves exist that have been and must be designed and constructed for all of the unique elements of the many designs of refrigeration systems using a multitude of fluids as circulating cycle refrigerants for different versions of the Carnot vapor cycle.
Therefore, there exists a need in the art for a universal refrigeration valve that overcomes the disadvantages of conventional valves, may be integrated into a refrigeration system without mechanical connections or machining of the inlet or outlet of the valve, interfaces with a plurality of adapter plates to perform any number of different functions, requires very few machining steps after forming or casting, will be inexpensive to manufacture, is formed or casted to very tight tolerances, has a long life without the need to internally service and other advantageous features.